Despite the negative impact of COVID-19, the composite material market is expected to growth of 5% within the 2026.
May 25, 2021
Market growth for thin composite laminates is driven mainly by the aerospace and defence industries, but new applications emerge nearly every day in other sectors.
One common factor is interest in extremely thin composite laminates, of variable length (depending on the application), with high performance mechanical, structural and resistance features.
For producing these laminates continuously, we developed an unwinding and molding line that produces an overlay, a pre-impregnated multilayer, with a maximum thickness up to 3mm.
Plant and process description
The unwinding section
This first section, the unwinding station, can accommodate up to 18 reels of prepreg composite material.
Depending on the desired laminate thickness, a series of rollers are unwound and the layers are passed through two pressure rollers, allowing constant and uniform dragging of the overlapping prepreg layers.
At this point the material passes on a roller conveyor where an electrical device welds the layers together and prepares them for the next phase where the operator can perform a visual inspection.
The consolidation phase
The material is driven into a hydraulic press with heated platens for consolidation.
The press, modularly structured to allow an even distribution of closing force, features a short-refrigerated area where the material enters. This precaution prevents resin from flowing towards the laminate entrance during the heating process, causing negative effects on part quality.
There is a dedicated unwinding system at the press inlet with two release films that prevent the material from coming into direct contact with the platens and adhering; the films are then rewound at the outlet of the press.
At the end of this process, the consolidated composite laminate obtained will have a final thickness according the number of layers used.
The heating module
After leaving the press, the material immediately enters a second heating station with radiating plates. In this phase, the material completes the hardening process, while the newly unwound portion of the laminate is consolidating in the press.
Final check and winding
Once ready, the composite laminate passes over a second roller conveyor for further inspection. To facilitate visual control of the laminate’s lower surface, an inclined mirror and dedicated lighting are incorporated.
A second couple of rollers guide the material (without adding additional tension) through a laser reader that checks the consistency of the laminate thickness. Finally, the material is wound on a motorized reel, easily transportable and usable in the subsequent processing stages to obtain the final product.
